The human body is exposed to a huge number of environmental contaminants. In this connection, organic substances of high volatility also play a role in particular, because they are released by various industrial and commerical processes in which industrial waste gases, automobile exhaust gases, and solvents Used in paints are released, and because they are present everywhere and are difficult to assess in terms of the effects they have. The same applies also to the dermal uptake of cigarette smoke, all kinds of sprays and suchlike from the ambient air.
Classical methods for analysis of air contaminants use, in particular, test tubes, for example manufactured by Dräger-Werke AG, Lübeck, Germany. These test tubes are generally made of absorbent material that contains color reagents and that shows concentration-dependent visible results concerning the concentration of certain gases and volatile substances. However, such test tubes are limited to individual substances and generally have a relatively low sensitivity because the reactions have a purely chemical basis. Moreover, they only indicate the concentration measured instantaneously, and not an exposure averaged out over a certain time interval. For an exact measurement of the concentrations in the air, it is also necessary for a defined amount of air to be sucked through the test tube, and this requires extensive test apparatus.
These systems have been overtaken by what are known as diffusion monitors which are already commercially available (manufacturer 3M) and which are relatively small and can be worn on the body. Such monitors contain approximately 180 g of activated charcoal in a Teflon matrix. These appliances are suitable for determining a number of organic compounds, for example acetone, chloroform, hexane, styrene, etc. The appliances are worn on the body as capsules with a clip and are analytically evaluated after they have been worn for a period of several hours. The measurement is done by organic extraction, for example by carbon disulfide. Disadvantages of this technique are that the analysis requires the use of solvents, and a difficult manual evaluation step is therefore needed. Such diffusion collectors cannot differentiate between inhalation of contaminants and dermal uptake of contaminants.
For dermal uptake of contaminants, formulations are required that are flat and can be worn on the skin. Such diffusion collectors to be worn on the skin have not previously been disclosed.
US 2003/0225362 A1 discloses a system and a method for transdermal collection of volatile substances. For this purpose, at least one collecting device is provided for retention and diffusion of an analysis sample obtained transdermally from a person's skin, and a detector system is provided for identifying and quantifying the analysis sample. The input data of the detector system are received by a logic module and stored, and they are compared to further data concerning the person and displayed as output information which is forwarded to another system and controls the operation of the collecting device and of the detector system.
WO99/13336 relates to a noninvasive transdermal system for detection of an analysis sample extracted from an interstitial fluid in or beneath a person's skin. The system comprises a dry chemistry component which interacts with the analysis sample and has a detection sensitivity allowing it to determine the analysis sample extracted from the interstitial fluid, and a wet chemistry component for transferring the analysis sample from the interstitial fluid in or beneath the skin to the dry chemistry component in a sufficient amount that the dry component can test the analysis sample.
U.S. Pat. No. 4,092,119 describes an environmental quality indicator comprising a polymer support layer onto which a color layer is applied as indicator, said color layer changing color under the effect of certain environmental contaminants. No diffusion or permeation processes take place in the support layer. The color layer does not constitute a barrier layer, it only provides a color change caused by chemical reactions of the indicator with certain environmental contaminants.
U.S. Pat. No. 5,203,327 discloses a system with which one or more predefined analytes can be determined in the fluid released through the skin. The fluids excreted through the skin by a person can thus be analyzed for the presence of certain substances. The system comprises a gauze layer which lies on the skin, and also a porous layer, a binder layer containing a chemically or biochemically active material for binding the volatile analyte, a gas-permeable filter, and a barrier layer that protects the system against contamination from the ambient air.
In this system known from the prior art, the fluids excreted through the skin by a person are analyzed for the presence of certain substances.